Why “clean” ingredients can quietly disrupt our hormones
A surprising number of natural, plant-derived compounds can mimic estrogen in the body.
These are called phytoestrogens, and they can be found in herbal supplements, skincare extracts, health foods like:
- Essential oils like lavender and tea tree
- Herbal extracts such as licorice root, dong quai, fennel, and red clover
- Tea blends marketed for “hormone balance”
- Seed-based oils, especially those pressed from flax, soy, sunflower, or sesame
These ingredients are promoted as calming, skin-soothing, and antioxidant-rich. However, many of them carry molecular structures that mimic estradiol. Your cells don’t care that it came from a plant or was marketed as “natural.” Our cells register the shape of the molecule and the signal it sends. If it resembles estradiol, it can behave like estradiol, contributing to estrogenic activity inside the body.
Some of the most common offenders include:
- Lavender + tea tree (documented estrogenic + anti-androgenic effects)
- Flaxseed oil (one of the highest phytoestrogen concentrations in nature)
- Soy protein powders
- Fennel, clary sage, red clover, hops found in teas and supplements
- Seed oils used in body oils, serums, and lotions
These phytoestrogens are found in common personal care products. They are often labled as “non-toxic,” “natural,” and “plant-based.”
Why are some plants estrogenic?
Many plants are naturally estrogenic because phytoestrogens are part of their built-in defense system. Plants can’t run or fight, so they use chemistry to protect themselves. One of those strategies is producing hormone-like compounds—especially isoflavones, lignans, and coumestans—that resemble estradiol just enough to interact with the estrogen receptors of animals that eat them.
These compounds can poison, slow down the fertility or reproductive cycling of predators, deter insects, or alter grazing patterns in ways that help the plant survive. The estrogenic activity is a deliberate biological strategy plants evolved to modify the biology of anything that consumes them. This is why even small amounts in supplements, oils, or extracts can meaningfully interact with human hormone pathways.
The molecules shown here, like genistein (soy), coumestrol (clover), resveratrol, and matairesinol (flax), have similar ring structures to human estradiol.
Because the molecular shape of these plant chemicals overlaps with estradiol, the human body allows them to bind to estrogen receptors and influence hormone balance.
Many people claim that phytoestrogens are safe because they are far less potent than estradiol, the body’s primary and most powerful estrogen. A few things to know:
- Estradiol (E2) binds the estrogen receptor with very high potency.
- Most phytoestrogens bind with lower potency, often 1/100 the strength of estradiol.
- But some, like coumestrol, are surprisingly strong, binding at ~1/20 the potency of estradiol.
- Genistein (soy) has moderate potency but activates certain estrogen receptors (ER-β) strongly.
- Lignans (from flax, sesame) are weaker individually but present in very large amounts.
So while these compounds aren’t “as strong” as estradiol dose-for-dose, they send the same estrogen-like signals, and can shift the body’s hormonal balance.
Hormones operate in picograms, trillionths of a gram. The doses needed to shift menstrual patterns, breast tissue behavior, or thyroid function are far smaller than most people realize.
When multiple products introduce small estrogenic signals every day, the body absorbs them into an already overloaded world of:
- Plastics
- Pesticides
- Fragrances
- BPA/BPS
- PFAS
- Pollutants
The wellness products layer on top of these exposures, creating a cumulative effect that quietly tilts the system toward estrogen excess.
Most people are not exposed to phytoestrogens once. They’re exposed:
- in foods (soy, flax, legumes, seeds)
- in skincare (plant extracts, essential oils)
- in supplements (herbal formulas)
- in teas (red clover, licorice, hops)
- plus xenoestrogens from plastics, pesticides, fragrances, etc.
Even if each plant estrogen is mild, the stacking effect matters. The body experiences it as constant estrogenic signaling, especially a problem if someone already has:
- low progesterone
- sluggish liver detoxification
- poor gut clearance
- history of birth control use
- estrogen dominance symptoms
When estrogen load is high, even weak plant estrogens can tip the system further toward excess.
Many cancer researchers also suggest that soy and flax are protective, but unfortunately the data is not consistent. A big reason is that many scientists claim the only thing that matters is the estrogen receptor: the idea that once the receptor is “saturated,” any extra estrogenic activity becomes irrelevant.
But this simply isn’t true. Estrogen doesn’t need a receptor to change cell behavior. It can act through non-genomic pathways (fast, receptor-independent signaling) that alter things like cell metabolism, ion channels, membrane fluidity, and inflammatory cascades. These effects happen within seconds and don’t rely on ER-α or ER-β at all.
So when people say “phytoestrogens are safe because they’re weaker than estradiol,” they’re only thinking about one mechanism. In reality, different tissues, different hormone baselines, and different doses make phytoestrogen effects incredibly inconsistent.
Studies regarding phytoestrogens are mixed. But it’s important to know that certain factors can alter study outcomes. For example:
- Different populations react differently. Studies mix together:
- premenopausal vs postmenopausal women
- women with high vs low progesterone
- people with fast vs slow estrogen metabolism
- people with very different gut microbiomes (which change potency!)
- Short-term vs long-term effects differ. Short trials may show a temporary decrease in estradiol. While longer-term exposure can increase estrogen receptor expression, making tissues more sensitive.
- Women with low progesterone may be more sensitive to phytoestrogens because the protective counterbalance is missing.
- PUFAs, endocrine disruptors, stress hormones, liver function, and thyroid status all influence how phytoestrogens behave once they enter the body.
However, we do have solid research on the effects of phytoestrogens on breast tissue via thermogram scans. Dr. Wendy Sellens is a breast thermologist and hormone researcher who is studying the impact of estrogens on breast health in real time.
She uses thermograms, infrared imaging tests that measure heat patterns and vascularity in the breast. Estrogen stimulates breast tissue by increasing cell proliferation, metabolic heat, and angiogenesis or vascularity (the growth of tiny new blood vessels that supply tissue).
When estrogenic compounds (including phytoestrogens) activate breast tissue, that stimulation creates localized heat and increased vascular patterns.
On a thermogram, this shows up as:
- hotter regions
- increased vascular activity (“angiogenic patterns”)
- asymmetrical heat compared to the other breast
- patterns associated with hormonal overstimulation
All of the scans below are from www.mypinkimage.com
Despite what many studies claim about phytoestrogens simply increasing or decreasing blood estrogen levels, Dr. Sellens’ research looks at what actually happens at the tissue level.
These patterns reflect how estrogenic stimulation shows up in real time within breast tissue. It’s a direct window into how the tissue responds, not just what’s circulating in the bloodstream.
Her research consistently shows that phytoestrogens (soy, flax, black cohosh) stimulate vascular activity in the breast, increasing heat patterns, blood flow, and angiogenic signaling on thermogram scans—the same kinds of changes seen with elevated estrogen exposure and increasing breast cancer risk.
In contrast, removing phytoestrogen exposure and balancing estrogen with progesterone cream has been shown to reduce heat patterns on thermograms, calm angiogenesis, and normalize breast tissue activity.
If you are concerned with estrogen dominance, it can be helpful to:
- Use coconut milk as a plant-based option instead of soy.
- Look for deodorants or lotions containing vanilla or citrus scents rather than lavender, mint, etc.
- Swap flax and soy-based protein powders for collagen, whey, or beef isolate.
- Avoid herbal blends marketed for “women’s balance” that contain black cohosh, red clover, dong quai, hops, or licorice.
- Opt for simple skincare (tallow) instead of plant-extract heavy formulas.
- Cook with butter, ghee, olive oil, or coconut oil, not seed oils, which worsen estrogen dominance by increasing oxidative stress + aromatase activity.
Exposure, accumulation, metabolism, receptor sensitivity, and liver burden all play a role. For some women, the effects are minimal. For others, especially those sensitive to estrogen or already overloaded, phytoestrogens can increase the estrogenic burden on the body.
I caution about supplements or products marketed as “natural” or “plant based” for this reason. Many herbal extracts can have effects just as powerful as certain prescription drugs. “Natural” doesn’t mean “safe.” And topical skincare ingredients can be absorbed directly through the skin, bypassing first-pass metabolism.
None of this means you need to fear food or avoid every herb. It simply means: know what you’re eating, taking, and putting on your body. If you’re already struggling with hormone imbalances, reducing additional estrogenic inputs can make a noticeable difference.